The verdict
Before I started the shave I noticed that the blades differ slightly in colour. I decided to have a closer look at the edge with a small 40x microscope. The blades do look very different - different colour and different honing pattern on the edge. I'm not expert enough to judge blade edges by looking at them under a microscope, I just noticed a difference.
Here was the plan: I'd put both blades in my Digress. Use the 'new' one for one half of the face first, then change blades and shave the other half of the face with my own PolSilver. I'd use Wickhams Club Cola soap, so I'd have at least something to smile about
I abandoned the plan after about five seconds. The 'new ' blade was not very sharp, but made up for this with plenty of tugginess. It was
Rough
(with a capital R)! There was no way I'd shave half my face in several passes with this blade. So I put my own PolSilver into the Digress, lathered up the other half of my face as well. The PolSilver performed as expected. Marvellous blade.
So is the new blade a fake? Let me put it like this: If it doesn't walk like a duck, doesn't quack like a duck and doesn't even look like a duck.. what are the odds that it is a real duck?
Blade binned. Second bladed locked away in the cabinet of horrors.
To sum it up: Either Gillette Russia have lost the plot, or the official Gillette distributer has been had. This ain't the PolSilver I love.